Thanks for the reply. One family tree I found says it was diphtheria, but I don't know where that came from; I'll check with town clerk. I initially thought that William McKay, son of Angus McKay, born about 1855, was a possible ancestor, but in a book on the history of Penobscot that I found on Google books said he died so I did find an index listing the death in 1862. So, dead end there. Maybe I can vacation in Maine someday.